Million Hearts model cuts heart attack and stroke risk without hiking Medicare costs

By Pooja Toshniwal PahariaReviewed by Benedette Cuffari, M.Sc.Oct 23 2023

In a recent study published in JAMA, researchers investigated whether the Million Hearts payment model reduced the incidence of cardiovascular events (CVS), including strokes, myocardial infarctions (MIs), and Medicare expenditure among Medicare beneficiaries.

Study: Effects of the Million Hearts Model on Myocardial Infarctions, Strokes, and Medicare Spending: A Randomized Clinical Trial. Image Credit: chayanuphol / Shutterstock.com

Background

Cardiovascular diseases (CVDs) remain a leading cause of mortality across the globe, thus warranting the development of strategies to identify associated risk factors and interventions for risk modification to improve cardiovascular health.

The Million Hearts payment model incentivized healthcare organizations to evaluate and decrease CVD risk. However, the long-term impacts of the model on CVD outcomes remain unknown.

Between 2017 and 2021, the Centers for Medicare and Medicaid Services (CMS) provided intervention organizations with one-time payments of $10 for each beneficiary for whom risk was evaluated. In 2017, CMS only paid intervention organizations $10 for each high-risk beneficiary monthly to aid cardiovascular care provision.

Subsequently, between 2018 and 2021, CMS made performance-based risk-reduction payments. To this end, CMS paid the organizations for high-risk beneficiaries to be re-evaluated annually based on their mean risk score changes each month.

About the study

The current trial was conducted between January 3, 2017, and December 31, 2021. A total of 342 United States-based healthcare organizations, including primary care, specialty practices, hospital outpatient care clinics, and health centers, were included in the study, which comprised 218,864 individuals.

The organizations were assigned to either the intervention group of beneficiaries (172 organizations, 130,578 individuals) or the control group of individuals receiving regular care (170 organizations, 88,286 individuals).

The sample population included Medicare recipients between 40 and 79 years of age without prior stroke or MI history and with medium-high cardiovascular risk. The intervention group organizations performed guideline-based care, including regular cardiovascular risk evaluation and care provision for high-risk individuals.

CMS paid the organizations to determine cardiovascular risk evaluation scores for the beneficiaries and rewarded health organizations for decreasing CVD risk for high-risk Medicare recipients with cardiovascular risk scores of 30% or higher.

Study outcomes included incident CVS such as transient ischemia, MIs, and strokes documented in the Medicare claims, incident cardiovascular outcomes in claims, and cardiovascular mortality from cerebrovascular disease or coronary artery disease, as indicated in the National Mortality Index data, and Parts A as well as B of Medicare expenditure for CVS. Cox proportional hazard modeling was performed to calculate the hazard ratios (HRs).

CVD risk scores were based on demographic data such as race, age, and gender, clinical parameters such as diabetes status, lipid levels, blood pressure, antihypertensive medications, and smoking status. Cardiovascular care services provided to high-risk beneficiaries included cardiovascular risk discussion, developing risk reduction strategies tailored to individuals, in-person re-evaluation visits each year, including recalculating 10-year cardiovascular risk scores using calculators, and additional contact two or more times annually to assess progress.

Study findings

The intervention and control group beneficiaries had comparable age medians of about 72 years, sex distributions of 58% and 59% males and females, respectively, race demographics, and initial cardiovascular risk scores with a median value of 24%. After a median follow-up of 4.3 years, 7.8% and 8.1% of the intervention and control group beneficiaries were diagnosed with incident cardiovascular diseases, respectively.

The likelihood of an incident CVS within five years was 0.30% less for the intervention group beneficiaries than the control. The five-year likelihood of combined incident CVS and related mortality was 0.40% lower among intervention group beneficiaries.

The model intervention group beneficiaries were associated with a 4.3% lower mortality rate, with a notable 14% lower mortality from coronary artery disease among those with high CVD risk compared to the control group. However, Medicare expenditure for CVS was comparable between the study groups, with effect estimates of a $1.80 reduction for each beneficiary every month.

Likewise, overall Medicare expenditure, including the Million Hearts model payments, was associated with an effect estimate of $2.10 for each beneficiary every month. Similar findings were obtained in the sensitivity analyses based on outcome definitions, population compositions, and regression specifications.

Conclusions

The Million Hearts payment model reduced the risk of new-onset MIs and strokes among medium-to-high-risk individuals by 0.3 percentage points over five years without significant changes in Medicare spending. These findings suggest that paying for cardiovascular risk evaluation and reduction could improve cardiovascular outcomes in the U.S.

Nevertheless, further research is needed to improve the generalizability of the study findings, as the pragmatic cluster-randomized trial may introduce potential biases and limit the study's accuracy. Long-term effects on healthcare costs may emerge over time.